LMV431/LMV431A/LMV431B Low-Voltage (1.24V) Adjustable Precision Shunt Regulators
May 2005
LMV431/LMV431A/LMV431B Low-Voltage (1.24V) Adjustable Precision Shunt Regulators
General Description
The LMV431, LMV431A and LMV431B are precision 1.24V shunt regulators capable of adjustment to 30V. Negative feedback from the cathode to the adjust pin controls the cathode voltage, much like a non-inverting op amp configuration (Refer to Symbol and Functional diagrams). A two resistor voltage divider terminated at the adjust pin controls the gain of a 1.24V band-gap reference. Shorting the cathode to the adjust pin (voltage follower) provides a cathode voltage of a 1.24V. The LMV431, LMV431A and LMV431B have respective initial tolerances of 1.5%, 1% and 0.5%, and functionally lends themselves to several applications that require zener diode type performance at low voltages. Applications include a 3V to 2.7V low drop-out regulator, an error amplifier in a 3V off-line switching regulator and even as a voltage detector. These parts are typically stable with capacitive loads greater than 10nF and less than 50pF. The LMV431, LMV431A and LMV431B provide performance at a competitive price.
Features
n Low Voltage Operation/Wide Adjust Range (1.24V/30V) n 0.5% Initial Tolerance (LMV431B) n Temperature Compensated for Industrial Temperature Range (39 PPM/˚C for the LMV431AI) n Low Operation Current (55µA) n Low Output Impedance (0.25Ω) n Fast Turn-On Response n Low Cost
Applications
n n n n n n n Shunt Regulator Series Regulator Current Source or Sink Voltage Monitor Error Amplifier 3V Off-Line Switching Regulator Low Dropout N-Channel Series Regulator
Connection Diagrams
TO92: Plastic Package SOT23-3
10095801
Top View
10095867
SOT23-5
Top View
10095844
*Pin 1 is not internally connected. *Pin 2 is internally connected to Anode pin. Pin 2 should be either floating or connected to Anode pin.
Top View
© 2005 National Semiconductor Corporation
DS100958
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LMV431/LMV431A/LMV431B
Symbol and Functional Diagrams
10095859
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Simplified Schematic
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LMV431/LMV431A/LMV431B
Ordering Information
Package Temperature Range Industrial Range −40˚C to +85˚C TO92 Commerial Range 0˚C to +70˚C Voltage Tolerance 1% 1.5% 0.5% 1% 1.5% 1% Industrial Range −40˚C to +85˚C 1% 1.5% 1.5% SOT23-5 Commercial Range 0˚C to +70˚C 0.5% 0.5% 1% 1% 1.5% 1.5% 0.5% SOT23-3 Industrial Range −40˚ to +85˚C 0.5% 1% 1% Part Number LMV431AIZ LMV431IZ LMV431BCZ LMV431ACZ LMV431CZ LMV431AIM5 LMV431AIM5X LMV431IM5 LMV431IM5X LMV431BCM5 LMV431BCM5X LMV431ACM5 LMV431ACM5X LMV431CM5 LMV431CM5X LMV431BIMF LMV431BIMFX LMV431AIMF LMV431AIMFX Package Marking LMV431AIZ LMV431IZ LMV431BCZ LMV431ACZ LMV431CZ N08A N08A N08B N08B N09C N09C N09A N09A N09B N09B RLB MF03A RLA MF05A Z03A NSC Drawing
DC/AC Test Circuits for Table and Curves
10095805
Note: VZ = VREF (1 + R1/R2) + IREF • R1
10095804
FIGURE 2. Test Circuit for VZ > VREF
FIGURE 1. Test Circuit for VZ = VREF
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FIGURE 3. Test Circuit for Off-State Current
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LMV431/LMV431A/LMV431B
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Storage Temperature Range Operating Temperature Range Industrial (LMV431AI, LMV431I) Commercial (LMV431AC, LMV431C, LMV431BC) Lead Temperature TO92 Package/SOT23 -5,-3 Package (Soldering, 10 sec.) Internal Power Dissipation (Note 2) TO92 SOT23-5, -3 Package Cathode Voltage Continuous Cathode Current Reference Input Current range 265˚C 0.78W 0.28W 35V −30 mA to +30mA −.05mA to 3mA −40˚C to +85˚C 0˚C to +70˚C −65˚C to +150˚C
Cathode Current Temperature range LMV431AI Thermal Resistance (θJA)(Note 3) SOT23-5, -3 Package TO-92 Package Derating Curve (Slope = −1/θJA)
0.1 mA to 15mA −40˚C ≤ TA ≤ 85˚C 455 ˚C/W 161 ˚C/W
10095830
Operating Conditions
Cathode Voltage VREF to 30V
LMV431C Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol VREF VDEV Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature (Note 4) Ratio of the Change in Reference Voltage to the Change in Cathode Voltage IREF ∝IREF IZ(MIN) IZ(OFF) rZ Reference Input Current Deviation of Reference Input Current over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance (Note 5) Conditions VZ = VREF, IZ = 10mA (See Figure 1 ) TA = 25˚C TA = Full Range Min 1.222 1.21 4 −1.5 Typ 1.24 Max 1.258 1.27 12 −2.7 V mV mV/V Units
VZ = VREF, IZ = 10mA, TA = Full Range (See Figure 1) IZ = 10mA (see Figure 2 ) VZ from VREF to 6V R1 = 10k, R2 = ∞ and 2.6k R1 = 10kΩ, R2 = ∞ II = 10mA (see Figure 2) R1 = 10kΩ, R2 = ∞, II = 10mA, TA = Full Range (see Figure 2) VZ = VREF (see Figure 1) VZ =6V, VREF = 0V (see Figure 3 ) VZ = VREF, IZ = 0.1mA to 15mA Frequency = 0Hz (see Figure 1)
0.15
0.5
µA
0.05 55 0.001 0.25
0.3 80 0.1 0.4
µA µA µA Ω
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LMV431/LMV431A/LMV431B
LMV431I Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol VREF VDEV Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature (Note 4) Ratio of the Change in Reference Voltage to the Change in Cathode Voltage IREF ∝IREF IZ(MIN) IZ(OFF) rZ Reference Input Current Deviation of Reference Input Current over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance (Note 5) Conditions VZ = VREF, IZ = 10mA (See Figure 1 ) TA = 25˚C TA = Full Range Min 1.222 1.202 6 −1.5 Typ 1.24 Max 1.258 1.278 20 −2.7 Units V mV mV/V
VZ = VREF, IZ = 10mA, TA = Full Range (See Figure 1) IZ = 10mA (see Figure 2 ) VZ from VREF to 6V R1 = 10k, R2 = ∞ and 2.6k R1 = 10kΩ, R2 = ∞ II = 10mA (see Figure 2) R1 = 10kΩ, R2 = ∞, II = 10mA, TA = Full Range (see Figure 2) VZ = VREF (see Figure 1) VZ = 6V, VREF = 0V (see Figure 3 ) VZ = VREF, IZ = 0.1mA to 15mA Frequency = 0Hz (see Figure 1)
0.15
0.5
µA
0.1 55 0.001 0.25
0.4 80 0.1 0.4
µA µA µA Ω
LMV431AC Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol VREF VDEV Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature (Note 4) Ratio of the Change in Reference Voltage to the Change in Cathode Voltage IREF ∝IREF IZ(MIN) IZ(OFF) rZ Reference Input Current Deviation of Reference Input Current over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance (Note 5) Conditions VZ = VREF, IZ = 10 mA (See Figure 1 ) TA = 25˚C TA = Full Range Min 1.228 1.221 4 −1.5 Typ 1.24 Max 1.252 1.259 12 −2.7 Units V mV mV/V
VZ = VREF, IZ = 10mA, TA = Full Range (See Figure 1) IZ = 10 mA (see Figure 2 ) VZ from VREF to 6V R1 = 10k, R2 = ∞ and 2.6k R1 = 1 kΩ, R2 = ∞ II = 10 mA (see Figure 2) R1 = 10 kΩ, R2 = ∞, II = 10 mA, TA = Full Range (see Figure 2) VZ = VREF (see Figure 1) VZ = 6V, VREF = 0V (see Figure 3 ) VZ = VREF, IZ = 0.1mA to 15mA Frequency = 0 Hz (see Figure 1)
0.15
0.50
µA
0.05 55 0.001 0.25
0.3 80 0.1 0.4
µA µA µA Ω
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LMV431/LMV431A/LMV431B
LMV431AI Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol VREF VDEV Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature (Note 4) Ratio of the Change in Reference Voltage to the Change in Cathode Voltage IREF ∝IREF IZ(MIN) IZ(OFF) rZ Reference Input Current Deviation of Reference Input Current over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance (Note 5) Conditions VZ = VREF, IZ = 10mA (See Figure 1 ) TA = 25˚C TA = Full Range Min 1.228 1.215 6 −1.5 Typ 1.24 Max 1.252 1.265 20 −2.7 V mV mV/V Units
VZ = VREF, IZ = 10mA, TA = Full Range (See Figure 1) IZ = 10mA (see Figure 2 ) VZ from VREF to 6V R1 = 10k, R2 = ∞ and 2.6k R1 = 10kΩ, R2 = ∞ II = 10mA (see Figure 2) R1 = 10kΩ, R2 = ∞, II = 10mA, TA = Full Range (see Figure 2) VZ = VREF (see Figure 1) VZ = 6V, VREF = 0V (see Figure 3 ) VZ = VREF, IZ = 0.1mA to 15mA Frequency = 0Hz (see Figure 1)
0.15
0.5
µA
0.1 55 0.001 0.25
0.4 80 0.1 0.4
µA µA µA Ω
LMV431BC Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol VREF VDEV Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature (Note 4) Ratio of the Change in Reference Voltage to the Change in Cathode Voltage IREF ∝IREF IZ(MIN) IZ(OFF) rZ Reference Input Current Deviation of Reference Input Current over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance (Note 5) Conditions VZ = VREF, IZ = 10mA (See Figure 1 ) TA = 25˚C TA = Full Range Min 1.234 1.227 4 −1.5 Typ 1.24 Max 1.246 1.253 12 −2.7 V mV mV/V Units
VZ = VREF, IZ = 10mA, TA = Full Range (See Figure 1) IZ = 10mA (see Figure 2 ) VZ from VREF to 6V R1 = 10k, R2 = ∞ and 2.6k R1 = 10kΩ, R2 = ∞ II = 10mA (see Figure 2) R1 = 10kΩ, R2 = ∞, II = 10mA, TA = Full Range (see Figure 2) VZ = VREF (see Figure 1) VZ = 6V, VREF = 0V (see Figure 3 ) VZ = VREF, IZ = 0.1mA to 15mA Frequency = 0Hz (see Figure 1)
0.15
0.50
µA
0.05 55 0.001 0.25
0.3 80 0.1 0.4
µA µA µA Ω
LMV431BI Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol VREF VDEV Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature (Note 4) Ratio of the Change in Reference Voltage to the Change in Cathode Voltage IREF Reference Input Current Conditions VZ = VREF, IZ = 10mA (See Figure 1 ) TA = 25˚C TA = Full Range Min 1.234 1.224 6 −1.5 Typ 1.24 Max 1.246 1.259 20 −2.7 V mV mV/V Units
VZ = VREF, IZ = 10mA, TA = Full Range (See Figure 1) IZ = 10mA (see Figure 2 ) VZ from VREF to 6V R1 = 10k, R2 = ∞ and 2.6k R1 = 10kΩ, R2 = ∞ II = 10mA (see Figure 2)
0.15
0.50
µA
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LMV431/LMV431A/LMV431B
LMV431BI Electrical Characteristics
TA = 25˚C unless otherwise specified Symbol ∝IREF IZ(MIN) IZ(OFF) rZ Parameter Deviation of Reference Input Current over Temperature Minimum Cathode Current for Regulation Off-State Current Dynamic Output Impedance (Note 5)
(Continued) Conditions Min Typ 0.1 55 0.001 0.25 Max 0.4 80 0.1 0.4 Units µA µA µA Ω
R1 = 10kΩ, R2 = ∞, II = 10mA, TA = Full Range (see Figure 2) VZ = VREF (see Figure 1) VZ = 6V, VREF = 0V (see Figure 3 ) VZ = VREF, IZ = 0.1mA to 15mA Frequency = 0Hz (see Figure 1)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device beyond its rated operating conditions. Note 2: Ratings apply to ambient temperature at 25˚C. Above this temperature, derate the TO92 at 6.2 mW/˚C, and the SOT23-5 at 2.2 mW/˚C. See derating curve in Operating Condition section.. Note 3: TJ Max = 150˚C, TJ = TA+ (θJA PD), where PD is the operating power of the device. Note 4: Deviation of reference input voltage, VDEV, is defined as the maximum variation of the reference input voltage over the full temperature range. See following:
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LMV431/LMV431A/LMV431B
LMV431BI Electrical Characteristics
(Continued)
10095807
The average temperature coefficient of the reference input voltage, ∝VREF, is defined as:
Where: T2 − T1 = full temperature change. ∝VREF can be positive or negative depending on whether the slope is positive or negative. Example: VDEV = 6.0mV, REF = 1240mV, T2 − T1 = 125˚C.
Note 5: The dynamic output impedance, rZ, is defined as:
When the device is programmed with two external resistors, R1 and R2, (see Figure 2 ), the dynamic output impedance of the overall circuit, rZ, is defined as:
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LMV431/LMV431A/LMV431B
Typical Performance Characteristics
Reference Voltage vs. Junction Temperature Reference Input Current vs. Junction Temperature
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10095862
Cathode Current vs. Cathode Voltage 1
Cathode Current vs. Cathode Voltage 2
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Off-State Cathode Current vs. Junction Temperature
Delta Reference Voltage Per Delta Cathode Voltage vs. Junction Temperature
10095863
10095861
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LMV431/LMV431A/LMV431B
Typical Performance Characteristics
Input Voltage Noise vs. Frequency
(Continued)
10095853
10095845
Test Circuit for Input Voltage Noise vs. Frequency Low Frequency Peak to Peak Noise
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Test Circuit for Peak to Peak Noise (BW= 0.1Hz to 10Hz) Small Signal Voltage Gain and Phase Shift vs. Frequency
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10095855
Test Circuit For Voltage Gain and Phase Shift vs. Frequency
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LMV431/LMV431A/LMV431B
Typical Performance Characteristics
Reference Impedance vs. Frequency
(Continued)
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Test Circuit for Reference Impedance vs. Frequency
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Pulse Response 1
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Test Circuit for Pulse Response 1
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Pulse Response 2
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Test Circuit for Pulse Response 2
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LMV431/LMV431A/LMV431B
Typical Performance Characteristics
(Continued)
LMV431 Stability Boundary Condition
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10095869
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Test circuit for VZ = VREF
Test Circuit for VZ = 2V, 3V
Percentage Change in VREF vs. Operating Life at 55˚C
10095866
Extrapolated from life-test data taken at 125˚C; the activation energy assumed is 0.7eV.
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LMV431/LMV431A/LMV431B
Typical Applications
Series Regulator Output Control of a Three Terminal Fixed Regulator
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Higher Current Shunt Regulator
Crow Bar
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Over Voltage/Under VoltageProtection Circuit
Voltage Monitor
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10095821
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LMV431/LMV431A/LMV431B
Typical Applications
(Continued) Current Limiter or Current Source
Delay Timer
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Constant Current Sink
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LMV431/LMV431A/LMV431B
Physical Dimensions
inches (millimeters) unless otherwise noted
SOT23-5 Molded Small Outline Transistor Package (M5) NS Package Number MF05A
SOT23-3 Molded Small Outline Transistor Package (M3) NS Package Number MF03A
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LMV431/LMV431A/LMV431B Low-Voltage (1.24V) Adjustable Precision Shunt Regulators
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
TO-92 Plastic Package NS Package Number Z03A
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